Question 1

Why did the improvement of microscopy techniques in the late 1800s set the stage for the emergence of modern genetics?

Accepted Answer

It allowed the study of meiosis and mitosis, revealing parallels between the behaviors of Mendelian genes and chromosomes.

Question 2

Thomas Hunt Morgan’s experiments with Drosophila melanogaster provided the first solid evidence that:

Accepted Answer

Chromosomes are the location of Mendel’s heritable factors.

Question 3

In Morgan’s experiment with white-eyed and red-eyed fruit flies, why did only males have white eyes in the F2 generation?

Accepted Answer

The white-eye allele is recessive and located on the X chromosome.

Question 4

Which of the following best describes a sex-linked gene?

Accepted Answer

A gene located on either the X or Y chromosome.

Question 5

A woman who is heterozygous for the X-linked gene for red-green color blindness (X	extsuperscript{N}X	extsuperscript{n}) marries a man with normal vision (X	extsuperscript{N}Y). What is the probability that their son will be color blind?

Accepted Answer

$$\frac{1}{2}$$

Question 6

In mammals, X inactivation results in:

Accepted Answer

One X chromosome being randomly inactivated in each cell, forming a Barr body.

Question 7

Which of the following statements about bees is accurate when comparing male bees to human males?

Accepted Answer

Bee males have half the DNA of bee females, whereas human males have nearly the same amount of DNA as human females.

Question 8

If a mutation occurs on the Y chromosome in Drosophila that reduces the size of males by half, which offspring will inherit this mutation?

Accepted Answer

All male but no female offspring of a male with the mutation.

Question 9

In cats, the O allele (orange fur) is dominant to o (black/brown fur) and is X-linked. What is the expected phenotype of an Oo female?

Accepted Answer

She will have patches of orange and black/brown fur due to random X inactivation.

Question 10

Which of the following best explains why triploid (3n) plants are usually sterile, while tetraploid (4n) plants are often fertile?

Accepted Answer

In meiosis, some chromosomes in triploids have no partner at synapsis, but chromosomes in tetraploids do have partners.

Question 11

Which type of chromosomal alteration is most likely to cause severe damage if an individual is homozygous for it?

Accepted Answer

Deletion

Question 12

A child is born with cri du chat syndrome, which is caused by:

Accepted Answer

A specific deletion in chromosome 5.

Question 13

Which of the following statements about crossing over is FALSE?

Accepted Answer

Portions of sister chromatids change places.

Question 14

A linkage map is constructed using which of the following data?

Accepted Answer

Recombination frequencies between genes.

Question 15

Which of the following is a type of chromosomal alteration that differs from all the others?

Accepted Answer

Aneuploidy

Question 16

A woman with mitochondrial myopathy is concerned about passing the disorder to her children. Which reproductive technology could potentially prevent transmission of the disorder?

Accepted Answer

Transferring her chromosomes into a donor egg with healthy mitochondria before fertilization.

Question 17

Genomic imprinting is best described as:

Accepted Answer

The silencing of certain genes depending on which parent passes them on.

Question 18

If two genes are 17 map units apart on a chromosome, what is their expected recombination frequency?

Accepted Answer

$$17\%$$

Question 19

Which of the following is true about the inheritance of extranuclear genes?

Accepted Answer

They are inherited maternally because the zygote’s cytoplasm comes from the egg.

Question 20

A male with Klinefelter syndrome has which of the following karyotypes?

Accepted Answer

XXY

ch 15 study guide

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드